Paints are applied to buildings and other structures exposed to the atmosphere in order to give protection against the weather and for decorative effect. Paints are not usually used in connection with radiation except for camouflage.
U.S. patent application Ser. No. 226,787 filed Jan. 21, 1981 relates to a camouflage material effective in the spectral range from visible light to radar waves having in sequence a fabric texture base, a soft plastic coating on the base, a metallic layer adhering to the plastic coating and a paint layer thereon wherein the metallic layer and paint layer in combination have an emission factor in the 3 to 5 .mu.m spectral region of between 30 to 70% and in the 8 to 14 .mu.m spectral region of between 40 to 85%.
U.S. application Ser. No. 495,354 filed Dec. 6, 1982 discloses a camouflage material of the above type comprising a base layer coated with a reflective conductive layer containing aluminum, copper or zinc which is reflective in the range of terrestrial thermal radiation and in the radar region of the spectrum and has a surface resistivity of not more than 0.5 to 10 ohms per square. This reflective layer is coated with a camouflage paint having reflective properties in the visible and near IR spectral regions similar to the natural warm background and incorporated in a binder having good transparency in windows II and III (3 to 5 .mu.m and 8 to 14 .mu.m, respectively). This reduces the emission contrast.
British Patent No. 1,605,131, published Dec. 6, 1981, discloses a camouflage object comprising a body having a surface which is highly reflective in the spectral ranges 3 to 5 .mu.m (window II) and 8 to 14 .mu.m (window III) and a coating of a camouflage paint on the highly reflecting surface. The paint contains a pigment having camouflage properties in the visible and near IR range and a binding agent and has an emissivity less than 90% in the spectral range of 3 to 5 .mu.m and 8 to 14 .mu.m. The emission power in windows II and III is "structure" by applying a priming paint comprising colors which are highly reflecting, in the manner of a clean metal surface, alternating with colors having a black effect in the long-wave IR range. "Structuring" may also be obtained by using a priming paint which is highly reflective and using a camouflage paint comprising pigments having different absorbing and/or scattering properties. A third method of "structuring" is obtained by using a primary paint which is highly reflecting and a camouflage paint with uniform pigmentation applied with locally different thicknesses. The binding agent suitably has a high absorption in the range from 5.5 to 7.5 .mu.m.
Infrared reflectors are compounds which reflect infrared energy. Infrared reflecting films have been used to coat windows in high energy laser systems (see, "Infrared Coatings for High Energy Laser Reflectors and Windows", Morris Braunstein, SPIE, Vol. 140, Optical Coatings-Applications and Utilization II, pp. 85-94 (1978). They have also been used to construct transparent heat mirrors for architectural glass coatings, light bulb envelopes, protective lenses, solar heat devices and the like. (See, "Materials for Transparent Heat Mirror Coatings", G. Haacke, SPIE, Vol. 324, Optical Coatings for Energy Efficiency and Solar Applications, pp. 10-15 (1982).